Knicks star Kristaps Porzingis (left knee) exits Thursday's game against Nets

New York announced Porzingis would not return shortly after star forward left game

There was a lot of excitement on Thursday night for the all-New York City matchup between the Knicks and Nets. Unfortunately, the excitement soon turned to worry as Kristaps Porzingis was knocked out of the game with a knee injury.

During the third quarter, Porzingis tried to contest a shot against Rondae Hollis-Jefferson and came up a little lame. He immediately pointed to the bench and after indicating to the training staff that his knee was bothering him, made his way to the locker room.

Porzingis immediately asked out of the game and, on the bench, seemed to indicate it was a left knee issue pic.twitter.com/ya4gdNNori

— Tommy Beer (@TommyBeer) December 15, 2017

A short time later, the Knicks announced that Porzingis would not return to the game.

Kristaps Porzingis (sore left knee) will not return.

— NEW YORK KNICKS (@nyknicks) December 15, 2017

After the game, coach Jeff Hornacek indicated Porzingis initially injured his knee in the first half, but stayed in the game and aggravated the injury in the third quarter. He added Porzingis will be examined by doctors on Friday.

Jeff Hornacek said Kristaps Porzingis originally tweaked his knee in the first half and it bothered him again in the third. Doctors will look at Porzingis again tomorrow. Unclear if ell get x-ray or MRI.

— Ian Begley (@IanBegley) December 15, 2017

It's not clear yet how serious or not serious the issue is, but this is certainly worrying, especially considering Porzingis has already had a little trouble with his knee earlier this season. And just in general, K.P. hasn't been the sturdiest player around.